1. Technical Field
The present invention relates to a circuit apparatus, an electronic appliance, and the like.
2. Related Art
A circuit apparatus for driving an object to be driven such as a DC motor is provided with an overheating protection circuit for preventing the circuit apparatus and the like from being broken by overheating caused by an overcurrent in the transistors constituting an H-bridge circuit. As techniques of the related art for such a circuit apparatus provided with an overheating protection circuit, techniques disclosed in, for example, JP-A-2005-347377 and JP-A-2007-82365 are known. These techniques of the related art implement an overheating protection function by disposing a temperature sensor unit in the circuit apparatus, detecting overheating due to an overcurrent based on a result of temperature detection performed by the temperature sensor unit, and turning off the transistors of the H-bridge circuit.
The techniques of the related art, however, do not give any consideration to the layout arrangement of the temperature sensor unit on the chip of the circuit apparatus. For this reason, there is a possibility that in the event of an overcurrent flowing between the source and the drain of a switching transistor in the H-bridge circuit to increase the temperature around the transistor, it takes time for the temperature increase to reach the temperature sensor unit, and as a result, the overheating protection operation is delayed. The delay of the overheating protection operation leads to problems such as the circuit apparatus being broken or the reliability being reduced.